SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56cf49eb03c1452387186261a06f508c2f8012b836148e6fd3931206fd64b4a5' 
  AND token = 'OoNWEioXyomgnfWnrdxwjY7Om11PLXtb6gXkgct9V4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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