SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ea40e3d2b2bee03b3fd03d9424e3b184a49de58daa4e69bcf321396f7473b46' 
  AND token = 'hhMscl4rfpAR09RhpdAMGcOdI3rHLerFUPAgWeTypSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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