SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a915d4e86b68d75288d66fe965f9fb130983b38d5d31861a71ca090a706bd5cc' 
  AND token = 'nDSu2u4xnvhqcTPvSW90Xod6kcuQ3WZOPTXmLWQuxuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}