SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7ab3a6cddddea67bffa3288c335f7647213750d7b12deae8442fae60e08ef295' 
  AND token = 'Jp3REUH5CqfQIvAO/DZFuGIEk33//NxEhfaOLPwz6Ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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