SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33c7c83d65dd7d2ad9dd1ce0977795704eeea4685bd741793cfd0ec0879b2ebb' 
  AND token = 'LRykuqOiyeuGvxz65c1VdOKx0hQg33wXbPvcggv1mss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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