SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a01883755f452fa44d297478c4a5938ce300229d6d30d72bb88a39a2147a004e' 
  AND token = 'DIA/el63SPjG4BYs7IUy/YoHzH0ebECz0usOzVhbrLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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