SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf73a4b6d0d14ca8294dd67f98f30bd65ea2423b4080a1780b5c53282d0cf560' 
  AND token = 'E53Q0zvDzjShdZsubYCAFEf7KbCzZrMTYfLPfWQeUjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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