SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '908e13c7a7028ba7be1f5f35a99954ee57f0e20ee003e1352f10cb59bdda1fa3' 
  AND token = 'xjGQvrzhZFjx2WgidUu5tRDXNxQUm2g2WyP23sKV2/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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