SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8669cb72be1667130a2927350f9329f42d34907077f7c755682cb05bbe8a6a45' 
  AND token = 'SvwUuoghHnNoUMSNmOKNuUNOpJ3V62Z+Spha/RCheR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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