Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9bc6a6aa6fe48c62d3898a3c3d76c6c78206f2b701da1729cd48dc787e4ef78' 
  AND token = 'U0uiVBkIBmFWMkSDLA414mf1fpVadvH5HR+G8S+3NPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}