SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59afac9635e9d9ded7111092aeb02bcbe9b5674fde0072ff9e714a9a5ce4b4c9' 
  AND token = 'PxH6TjFWWMEqsBNmOwz3JUgyz06+AxDU1qQUXlC5oy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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