SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4143dde03c72281c2b726e2fdb9970dfc7a75d5335415d8f18fadc2c4e65279c' 
  AND token = 'OYbxKvi204dJxAh4NB6AyTply1KAXcTJIaDSksb4IF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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