SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9ec91f56020f3fe619e66887f76db9d58a7eafc90ca40c9f4f60b8245ebf7a' 
  AND token = 'AcW551ab/sQVJtMikFui/N60hoDK0EvEsXaG6Bnn6XE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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