SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f018e7ac76a545b877e7a782e3e153a84b42ead5ac8172451133afbe1d43cde' 
  AND token = 'UjlBHwPornaBXxb/teoP/+Lm7W3hMLnI3tNCPQVWrmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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