SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f265c302e410cdf875e813f4976262902a14a97bf43a9b578cd68cbdc12d8c2' 
  AND token = '2LyqUjhHzDy5QVKEjkXIp4K0sJGiErPoLNJw63oG+PI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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