SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '420500ca38670ddea43421f022147c9dd0010eaabb55b74c27d9579f1a082fe0' 
  AND token = 'IuU6awOHvvHtTkTKtB1DPPOG45JKBVeF7W+dpi1G8JE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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