SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cc4ad9082bd7d55bbbffe9db702ebaf3a6421fe1695491ca94284ec391fb044' 
  AND token = 'VSonQz1lztO+MnBYKJ4/wPJ+uHclCF9/KcREXmAtIAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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