SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6e7a7c6d879b81fe5e7656280cd0563616bf0afab934df78750b4168ff939ab' 
  AND token = 'K1RwHgYARGJyjyoSXPlp5k9GQZ2gTSoJUX3Wjs+8m64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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