SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af93de68622234c9cad1c8d0165b0cb439847a08da417e618dd3fe53a6207be' 
  AND token = 'PBMJK+77TCaAracZ5jw/WkrUCGUGiLWZQpr0sNtRk20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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