SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '597e18fc29bda409d6c0e0a2f506fea96a75bbe95bbf09dc7d8c59573ba53196' 
  AND token = 'BHSN2hhvLl8RjRUFYyw2o66FPp8FcAGP0s6iLciy6uY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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