SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd20c2dd92aea529a47000aa8a4f4e13005a73c1d4d0475ebfef4da32417c66' 
  AND token = 'UVLJD5vNj9eQuzy/G7+l4ARqwjwxAmYtJLiYx9/iZU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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