SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd01310a533ae21ac74f95c5664843ffc33715201a1572d6d71b3c240960f70c' 
  AND token = 'Iu82o82LRSl8XRGZxj28m8ua6fv5hYpCnHI6SY//5Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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