SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5531efbe4e2b742048145141e3a634528f3de6239e85a5d172948ed2aba63664' 
  AND token = 'KGIrwaV/mlYeAdIs8QQNTyn9NXFi7+SxHIiNPMuK60Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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