SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39590b8fdfa056b73c8fc04165abf34f7858f4b34ef1f93d28aa9429dc066dba' 
  AND token = 'IBSo+0QBmxC+Vipp4LdvBwRPpeJ1mBaeg6wXahShTqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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