SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '74ecea5ad35f87c845361040c5be4f4308842f29a61925b6a066ec3173f7c2c7' 
  AND token = 'J4/cn5VYOIACVe5o19OGu3tpzBEMIZWBuNLKEuYWabg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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