SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05823fb4f5100054620c0479514f60554faa075f3374aa9bec6e00d8511e12a6' 
  AND token = '2I7RMfpKaKQeC2y4eMZCCnKYLWVfmEbm6Ua5olBALEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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