SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '099d462ec0b4844aab69b4a7f5766c004ff29d17ce837fc6f5334234bb4b1e49' 
  AND token = '7/RJsxRHa1a3RGiwPnqoSBCKyW7nGFeFA3zE432abm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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