SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e469c0d8192f0b1c1842944dfbdab6769dd9963a1b13ecac8f94b74cf7b2896' 
  AND token = 'Scz468UQI/YDHpzU8RD6q0iJ2ICIj5MLLmBQPIDMTik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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