SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4977841155356eb04a1938f6f5139736a9420b872a830e7783dc880eec9243b' 
  AND token = 'gBZqPC3vicZJN+zlnAY7QMFc2/lTKgeNS5UNGrn5dTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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