SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e726d2d58d80c7b88d73ca53d4abb473d5531de98b97efecc03fbaf87b808c1b' 
  AND token = 'LDgpScCDJtC40+iM5BHzgiartTNFSesE6OcNVjjHpSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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