SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab81c3adf0eafbcb7f6ec52d2f61059f97499b2f8c59222e13e4bb655d91d4d6' 
  AND token = 'hBpXzsrwco1xVEUOgzVHexv8EwUrGQ/Vwm99LT2p0Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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