SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2173789f75376e748624c9c540f01d12f84e14707315bb6df2d2fed3da30d666' 
  AND token = 'Mobh310LpJZB2fvTNjHe9XxUJtvK7sHwPdqVhJ56mf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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