SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a8814defded5bbcb6923984bfdbaca45b78d3339b6749072ba27a47a6df312e' 
  AND token = 'G8SmXm2oGiPwra6oDqBbivO6pbsH1DpU+vWzZVGetBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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