SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03660eb7af300669a3413c9c9c67b77e517804db5f7a878322f7897cf8521bd9' 
  AND token = 'BWxwlCOygh9wCxgPpjRTicgGnrxtnPUBSN0EHA4p+J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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