SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fcb654e913c2cfff4a94449c54479dd3a5534aefe93cf519f646ad762457ed0' 
  AND token = 'eWDuvRIKt5uNG2oVK860ObBEDmNP+vi/N75pg9SdMfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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