SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e2e948f5d64d76b847cbb09d130c47ed74f27cae9c29f1015d068c593f6e16b' 
  AND token = 'D3KkiF5khuATlfG2cm0PWm0Qmgne1DIcPqXZpDzdFDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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