SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '071276562f6517d8090537f524e403a6b70d7ce846223a18f179e659fa3d9149' 
  AND token = 'EumNsnNcMXdYduLuGy3DNJJI+BxToXsh7NNHIb5Ai0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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