SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ebf5d100f3b672faa494da13f87802cb13d098e4fc7ef9d4204a6263c74e9e9' 
  AND token = 'VE2qcAp5viKrPSBiKz3Ejkw9CzfzVIl4UQg7Q0jL2a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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