SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a145832d2e18aaccb2f0d493a6babb364df47d0d1138b19eefb49543bba3bf1' 
  AND token = 'txXT+c4ky+xKIaOXStADQ2meJR9vts5hHqwJN5kJwxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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