SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43ffe3e58858c7a6a7274d40dad329314e3a3b9d29d21ba6d510f05d5836057b' 
  AND token = 'ZAXJRWYTUmL5zKphfmNVjSkvTk4KXgOotLp7ENkaNOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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