SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f950fd4fac5ad2413e86f0cdc748a7002ba8fd57e2b156be0850c496a41099e7' 
  AND token = 'vTRP5CPQu1qC2GR/+qyCEshsOBtArJndXFsMVE/vxYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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