SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7927bf0d45cdd454e1410cad92f2259f6ada1d38bce6f5978208ddeb6b88245a' 
  AND token = 'bQuI86YAEjgPiGouRLjeZTlgHDpjqmye2h8wxk8JRJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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