SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '32f0bad5ccf4a52e8ede144352aa1a65e58261817fe12632ed7372b90cf3a403' 
  AND token = 'S+jJ0phFYxMBJYfuuv0yRP7D8oXR1CI6QBhS9UKkmDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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