SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52e7caeb6c6d3f109905c610675d096ba510d6b84be91dd9933b9686a2322922' 
  AND token = 'wEL2ghDheBWn1UGXUsxbUIR128YOhXFKXr7/crqz/Hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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