SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '809462bedcd27f5503a619aaba32badbd41c7c323cd7eb6be1478401689f55ce' 
  AND token = 'lwbo9icVYlM2SGEriVZxsklfogXMldjbr7AdXFVprAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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