SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20090626585c4952271a5dbd2be8cf1b9bd666653b487755196855f7b7ad4741' 
  AND token = 'DbRzIKUaxGew6q1bx9eh2zSKYJ5AfVNQgBztevq7LYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}