SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '568c60b09880f7a954b3c63be54e0bd6b38b0ffcf57e820185fbf6e6f9462f0f' 
  AND token = 'PVvqqr/0erZgmN3jA38xdaTQarFaKmHFpbTQ2I7qlY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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