SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35aa5259a12b8fea6cd2535227cbd3cedbcc8aacf5be9c027f6ccebdf4340d8e' 
  AND token = '6Ce7mfDcvd5MzS5s3uYnM8G84nJc7wXwQ/z96+hF+6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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