SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0af8b9b067d7025e7049751c2f619912b46e371d9426ead1ad1290a131ec92a9' 
  AND token = 'sAXmGnklbB+ic1SKCGuCl+oi3KWAtphwfEg0OrAZxY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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