SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b23af948d0d41db995dc055d66f04dde06ede4106a5fe3ac2542bfaa64d628d' 
  AND token = 'KnmMerTvc8aqmbw/+SuwpQnCEQeDRRwlNYYcHWVMoQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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