SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fad73a1f1093d4d4262d28438dba2d816fd86ee0e778220e9b3c71e330be1df' 
  AND token = 'XovY3N+CBDuqZglNP/B14C7EZgXqt/v5weStPa6DX78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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