SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '341dd6a9942f8f4c338b22f0e472702e782f3c1ab101cfc54c1d89f7dd833444' 
  AND token = 'DYWSuFKl9Z4TSGbY4yHqYmnwyhTGwqVaB/b4UFG8qWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}