SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c865081e135371765c45767d24ccd80dc26a7e532d6d665cef56e9c911130d7' 
  AND token = 'mUP0O1aIGKJUW8QO1Lt/LKTN0FoFN2AvPZFQeIHmVHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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