SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e4c3922e68798cf43ca0d2365715c96c57bd0750366ce2300b2620610e87435' 
  AND token = '47/rghfDIr59cID6/b1fzgz/McfobjHk2an2kTRt4PU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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