SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e439ca91fee042b7a5259a52a32fee21f356507765c684ad53e1be8981c694e6' 
  AND token = 'SBo2Agpo5wGUAj3nqlzQY3/Kug4zcmVLmSiNtNYhP0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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