SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'add7487e42aaf2dd46d4abe160eae97d73978dbab52ae8cb7812a88d9429808b' 
  AND token = 'aM5HBUMDMakvWDh72U7nxc8MCJtPTG5YpG8/395mSrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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