SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3c2efcce5ad43875ad2f6bc40121b481f33b32b3216686c5f8cc910f16792e' 
  AND token = 'qYxUaKy+QZ0jL66nNEjRjjgVrqXrhGHPvqaUzNAf8MI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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