SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '566c800d926d5c9696e7c0df352953476c9bd3adcec439c92ce4e273131a695e' 
  AND token = 'SpWuWmVKfToK3m8nxjENV56u4BV1v+PO5V0WMRllH0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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