SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a19efb388826a8da49a9300cfb057e61a4e5cacaca8aa782c1e95827477574b' 
  AND token = 'MzMoAxXiC3gMdFVhE9vN3eMFbXKwGyEjK3KqwiWchdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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