SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c775c6b9e2dfb258b6bcb8416d66ad7db6bada7317d7375642ecef6c0653d8b2' 
  AND token = 'Ye+XwuIxYg8LoogdhBkCzI13N5WTZrQa7sv9clTTt6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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