SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e0cd66936f332a2cd7d03dd6228e93bb4502648e7b7b1a8ff2caa53b21ba6d4' 
  AND token = 'fuSlyKc2FOrkUNgGWY9ECtOBoYPQnM0GtjQcJ8q+pwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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