SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '031432a56af9694f62c7fc191e2ecd806f61ce44877ed150d43621213ba05b40' 
  AND token = 'gSIMj8XUE+u+rYCZf8kyl3sg3T0Zy+/Uhzrg6Dq2F5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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