SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dfeeadcd9dbffd4f612c3fad7b5b6e866e55cd550cb5686762d1d7fa51d10e6' 
  AND token = 'z59c7J0na9tpiF4D9zmsJDKjPihLBhq1Cq7bmANZkxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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