SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ab84a46a81ce032299d8aafdf114a060ec4d670faa8273436506bb8c072bf4' 
  AND token = 'LfrUj/6i1777VgU5gRvCnrXDUuc6PySgTaO3ky8Vet0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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