SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87a05a1e316d6d4c6d6bab53348a447b2c61c917339f6c659b67f887b0b35d3c' 
  AND token = 'dBYboDsmkmWUU+pQ2W+DqF3yH6/znNICavtgzGhirw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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