SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4e486f06d07c8ce829a643a690daacf28722857fee67ee293ecc947a24475c7' 
  AND token = 'oEQIRhOchaA0PqxutRQYhbC90CECj/veBe7z+YCrFRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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